Liquid crystal display (LCD) devices have advantages of thin bodies, energy saving, and zero radiation, and therefore are widely applied. Most of the traditional liquid crystal display devices in the market are backlight type liquid crystal display devices, each of which includes a liquid crystal panel and a backlight module. The working principle of the liquid crystal panel is that: liquid crystal molecules are put between two parallel glass substrates, which have a plurality of perpendicular and horizontal thin wires therein, and the liquid crystal molecules are controlled to change their directions according to on or off electric currents, so that lights of the backlight module can pass through to create images. That is, because the liquid crystal panel itself cannot emit lights, it needs the lights provided by the backlight module to normally display the images. Therefore, the backlight module becomes one of the most important components of the liquid crystal display devices. According to difference incidence position of light sources, the backlight modules are divided into two types: an edge lighting backlight module and a bottom lighting backlight module. The bottom lighting backlight module is disposed light sources, such as a CCFL (cold cathode fluorescent lamp) or an LED (light emitting diode), under the liquid crystal panel, so as to directly form an area light source for the liquid crystal panel. The edge lighting backlight module disposes a light source, such as an LED light bar, under and beside the liquid crystal panel, so that lights of the LED light bar are emitted into a light guide plate from an incidence surface on an side surface thereof, and are emitted out from an emergent surface on a top surface thereof after being reflected and diffused, and then pass through an optical film set to form an area light source for the liquid crystal panel.
FIG. 1 is a schematic view of an LCD module of a traditional technology.
Refer now to FIG. 1, an LCD module comprises a printed circuit board 102; a liquid crystal panel 101 connected with the printed circuit board 102 through two flexible circuit boards 103; and an array light source of light emitting diodes disposed between the printed circuit board 102 and the liquid crystal panel 101, wherein the array light source of light emitting diodes comprises a plurality of light emitting diodes 104 and a substrate configured to carry the light emitting diodes 104. The light emitting diodes 104 are evenly arranged in a middle area between the liquid crystal panel 101 and the printed circuit board 102. Projections of the flexible circuit boards 103 on the substrate overlap with the light emitting diodes 104. Because the light emitting diodes 104 disperse heat when in operation, and more particularly the flexible circuit boards 103 are easily heated by the light emitting diodes 104 which are in the overlapping area, the performance of a liquid crystal display device is influenced.